Agenda

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C. 3

To:	Board of Supervisors
From:	Brian M. Balbas, Public Works Director/Chief Engineer
Date:	October 20, 2020

Contra

Costa

County

Subject:

APPROVE the Storm Damage Repair, Bear Creek Road Project and take related actions under CEQA.

APPROVE	OTHER
RECOMMENDATION OF CNTY ADMINISTRATOR	RECOMMENDATION OF BOARD COMMITTEE

Action of Board On: 10/20/2020

APPROVED AS RECOMMENDED

OTHER

Clerks Notes:

VOTE OF SUPERVISORS

AYE:

John Gioia, District I Supervisor
Candace Andersen, District II Supervisor
Diane Burgis, District III Supervisor
Karen Mitchoff, District IV Supervisor
Federal D. Glover, District V Supervisor

Contact:	Sandeep Singh 925-313-2022
cc:	Ave' Brown Sandeep Singh

I hereby certify that this is a true and correct copy of an action taken and entered on the minutes of the Board of Supervisors on the date shown.
ATTESTED: October 20, 2020
David Twa,

BY:	, Deputy

RECOMMENDATION(S):

APPROVE the Storm Damage Repair, Bear Creek Road Project (Project) and AUTHORIZE the Public Works Director, or designee, to advertise the Project, Briones area. [County Project No. 0672-6U6226, DCD-CP#19-40] (District I, V).


DETERMINE the Project is a California Environmental Quality Act (CEQA), Class 1(c) Categorical Exemption, pursuant to Article 19, Section 15301 of the CEQA Guidelines, and

RECOMMENDATION(S): (CONT'D)

DIRECT the Director of Department of Conservation and Development to file a Notice of Exemption with the County Clerk, and

AUTHORIZE the Public Works Director or designee to arrange for payment of a $25 fee to the Department of Conservation and Development for processing, and a $50 fee to the County Clerk for filing the Notice of Exemption.

FISCAL IMPACT:

Estimated Project cost: $1,290,000. 100% Local Road Funds.

BACKGROUND:

The purpose of this project is to reconstruct the road embankment and stabilize the roadside shoulder in two adjacent locations along the northbound lane of Bear Creek Road, approximately 1.3 miles south of Bear Creek Road’s intersection with Alhambra Valley Road. The slide at the northern location has compromised a portion of the northbound lane and has been closed off with concrete k-rails and covered by plastic. Traffic has been reduced from a two-way road to a single lane road with stop signs installed on both sides of the slide. The slide at the southern location has not yet affected the roadway, and has been covered by plastic. Repairs of both embankments are necessary to prevent further deterioration of the roadway section and roadside shoulder, and to restore the northbound lane to its original state.

At the northern slide location, the project will require installing an approximately 72-foot long soldier pile retaining wall along the north side of the roadway to support the reconstructed roadway. The piles for the retaining wall will be set via drilling; no pile driving will occur. The anticipated maximum excavation depth is 39 feet for the piles and approximately 12 feet at the base of the retaining wall where timber lagging will be installed. One drainage inlet will be established in place of an existing catch point. A hot mix asphalt (HMA) dike, guardrail section, and minor concrete vegetation control will be constructed along the top of the reconstructed slope.

At the southern slide location, the project will consist of regrading the slope and roadside shoulder. The project will require excavating the failed material within the eroded area and regrading with imported fill material to a maximum slope of 1.5:1. An HMA dike, section of guardrail, and minor concrete vegetation control will be constructed along the top of the reconstructed slope.

Some debris and sediment removal may be required in the slide area and the upstream drainage ditch. Roadway surface drainage will be restored to previous conditions. Equipment staging will likely occur in the northbound lane between both slide locations. Channelizers and k-rail may reduce lane width at both sites and the equipment staging area for the duration of construction. One oak tree and one bay tree will be removed. Construction is currently anticipated to occur in the summer of 2021 and take approximately 30 days to complete.

CONSEQUENCE OF NEGATIVE ACTION:

Delay in approving the project may result in a delay of design, construction, and may jeopardize funding.